Height adjustable work chairs are standard in today's seated workplace environments. The most common height adjustment mechanism for work chairs utilizes a spring driven mechanism, most commonly, the locking gas spring. Since a spring driven height adjustment mechanism only powers the chair seat upwardly when the chair user reduces downward force to the spring which supports the chair seat, the maneuver for current chair design requires the chair user's legs to lift the chair user from the chair seat while the chair user awkwardly reaches with one hand to locate and lift an unmarked height adjustment lever which is usually located out of user's visual range, fashionably concealed beneath the chair seat. This puts the chair user in an awkward position, especially in a way that relates to positioning her or his height to a specific work task. And typically, the height adjustment lever is mixed in with other visually concealed and unmarked adjustment levers used to adjust seat tilt or backrest tilt, oftentimes occasioning the user to actuate the wrong lever. There is a need for some chair users performing certain tasks to adjust the height of their chair while remaining in a stable focused position on the chair. In a multiple user situation where several users share usage time on the same chair, the multi-user chair would need to be height adjusted for users of different body measurements. If, for example, the multi-user chair were used in a laboratory setting to seat multiple users at a microscope, it may sometimes be necessary for a user to adjust the height of the chair to obtain appropriate eye level for the ocular setting due to limitations of the ocular setting on the microscope. With chairs currently available, the awkward maneuver required for adjusting the height of the chair upwardly, more or less necessitates that the user speculate how far up to adjust the chair while employing trial and error to obtain the sought after adjustment. This current method usually requires more than one attempt to get it right. In other laboratory uses, when high stool type chairs are used to seat laboratory workers at counter height work surfaces, the chair needs to be adjusted at a height that oftentimes suspends a worker's feet above the floor rendering the worker unable to push her or his weight off the chair seat for further upward height adjustment. In this situation, the worker must jump off the chair, and while standing, adjust the chair upward, speculating at the needed height adjustment. Then the worker must climb back on the chair to see if the adjustment was on target, many times having to readjust the chair a second or third time. In office settings, this same inefficiency with current chair designs exists, but is less noticeable due to lesser functional requirements demanded by the work task, or by the worker. In various work settings height adjustable chairs allow a number of workers to use a specialized piece of equipment such as a drill press or assembly line machinery. Efficient upward height adjustment is not only necessary for worker efficiency, but also to allow the worker accurate adjustment of user's working height appropriate to the work equipment. In situations where chair height adjustment is needed, the most efficient and accurate upward adjustment of chair height is while the user is in the chair. An alternative for achieving the benefits of this invention would be the use of an expensive electric powered chair, attendant with power consumption costs, and the necessity of spatial support requirements related to power cord and/or battery weight, and battery recharging paraphernalia. There is a need for a relatively inexpensive height adjustable chair that provides a seated worker upward chair height adjustment while the worker remains as suitably disposed in the chair as possible to the work task to which the adjustment is being made.
All patents, patent applications, provisional patent applications and publications referred to or cited herein, are incorporated by reference in their entirety to the extent they are not inconsistent with the explicit teachings of the specification.